The influence of the polyphenols of cider on plasmin and plasminogen activators

Preliminary findings suggested that the inhibitory activity on fibrinolysis produced by most varieties of cider is due to their content of polyphenols. In particular, the inhibitory activity co-eluted with the brown coloration on gel filtration, was removed by adsorption with polyvinylpyrrolidine, and was greatly reduced in a type of cider with a low concentration of phenolic compounds. The individual polyphenols of apple juice and ciders were examined for their ability to inhibit tissue activator, urokinase and plasmin. Neither phloridzin nor chlorogenic acid had any inhibitory activity at concentrations of 500 micrograms/ml while epicatechin had only a slight inhibitory effect at this concentration. The procyanidin fractions were markedly inhibitory on urokinase-induced clot lysis, the amidolytic activity of plasmin and on the fibrinolytic activities of plasmin, urokinase and tissue activator on fibrin plates: inhibition was noted at concentrations as low as 0.25 micrograms/ml. The order of inhibition was polymer greater than oligomer greater than trimer greater than dimer.